Augmented reality refers to the process of superimposing useful information, generated by a computer, on an image and then combining or augmenting them via computer programming them when an image or photo is displayed. In plain words, augmented reality refers to the process of superimposing a 3D virtual object on the real world and then displaying them. An example of an apparatus using augmented reality is a head-up display (HUD). An HUD is applied to the canopy or helmet of a fighter plane or tank, and enables a pilot or tank operator to view various types of information while viewing geographic features. Currently, people can often see an HUD being applied to a vehicle and displaying information, such as speed or the like, on the windshield of the vehicle.
Another example of augmented reality is a glasses-type apparatus known as a so-called “Google Glass.” Such a glasses-type apparatus equipped with a depth of field control function for enabling augmented reality implements augmented reality by superimposing a real world image and a 3D virtual image on each other and then displaying them in a field of view when a user wears the apparatus in the same manner as he or she wears glasses.
FIG. 1 shows a conventional glasses-type apparatus for enabling augmented reality. “Patent document 1 (KR 10-2014-0053341 A)” discloses the conventional glasses-type apparatus for enabling augmented reality. The conventional glasses-type apparatus for enabling augmented reality includes a projector 1 configured to generate an image, a transparent prism 3 configured to reflect the generated image to thus enable the image to reach an eye of a user, and a frame 5 configured to fasten the projector 1 and the transparent prism 3, and enables a user to simultaneously view an image reflected by the transparent prism 3 while viewing a real world image via the transparent prism 3.
However, the conventional glasses-type apparatus for enabling augmented reality, which is disclosed in patent document 1, surface-reflects a planar image, generated in the projector 1, via the transparent prism 3. Accordingly, when a user focuses on an object in the real world, it is impossible to focus on a virtual image generated in the projector 1, and thus a problem arises in that the user cannot simultaneously focus on both the object in the real world and the virtual image.
Furthermore, the conventional apparatus uses the transparent prism 3, and thus the apparatus has some weight and volume. Accordingly, it is inconvenient to wear the conventional apparatus, and the conventional apparatus is disharmonious because the appearance of the conventional apparatus is different from that of typical glasses or sun glasses.
Moreover, the projector 1 and the transparent prism 3 are installed in front of a single eye, and thus images viewed by both eyes are different, thereby causing inconvenience (when projectors and transparent prisms are installed in front of both eyes in order to solve the above problem, the weight and volume of the apparatus are increased, and thus a problem arises in that the conventional apparatus slides down while a user is wearing it or it is difficult to wear the conventional apparatus for a long time).